Casio Men's G-SHOCK Solar Watch with Bluetooth, G-STEEL Small Model, Metal Band GST-B400D-1AJFProduct Highlights strong> Achieving further miniaturization of components and thinning of modules. While keeping a slim profile, it also maintains high functionality with Bluetooth and solar power, significantly reducing power consumption. Additionally, with the carbon core guard structure, it achieves the thinnest in the G STEEL series (as of December 2020) while maintaining impact resistance. From the back to the top of the bezel, it measures 12.